1. Field of the Invention
This invention relates to a cardiac monitoring apparatus and method for monitoring a user's heart rate, or other parameters derived from heart-beat sensing.
2. Description of Related Art
Heart rate is a physiological parameter that is measured in a wide variety of situations, for example to determine the health status and fitness of a person or animal. It can be used, for example, to give a measure of energy expenditure of an individual and a number of devices exist for doing this by converting heart rate to calories used. Conventional systems comprise a belt worn around a user's chest and carrying a heart-beat sensor and a radio transmitter for transmitting measured data to a wrist-worn display unit.
Such conventional systems suffer a significant problem in that correlating heart rate with calories used may only be effective for exercise rates achieving significant heart rate increases. Smaller increases in heart rate can be due to, for example, stress rather than physical exertion and may therefore be misinterpreted by heart-rate monitoring systems.